21165207140 has 48 divisors (see below), whose sum is σ = 55414364544. Its totient is φ = 6596947200.

The previous prime is 21165207137. The next prime is 21165207169. The reversal of 21165207140 is 4170256112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6870281 + ... + 6873360.

It is an arithmetic number, because the mean of its divisors is an integer number (1154465928).

Almost surely, 2^21165207140 is an apocalyptic number.

21165207140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21165207140 is an abundant number, since it is smaller than the sum of its proper divisors (34249157404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21165207140 is a wasteful number, since it uses less digits than its factorization.

21165207140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13743668 (or 13743666 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The spelling of 21165207140 in words is "twenty-one billion, one hundred sixty-five million, two hundred seven thousand, one hundred forty".